Phototherapy method for treatment of acne

Abstract

The present invention is directed to methods for treating acne. The methods include exposing the subject afflicted with acne to ultraviolet light having a wavelength between about 320 to about 350 nm, such that the acne is treated, e.g., inhibited, diminished, eradicated or prevented. In a preferred embodiment, the wavelength is 335 nm and is emitted by either a nitrogen laser or a third harmonic of a NdYAG laser. Treatments can be administered over a several week period, where the subject is exposed to sequential doses of ultraviolet light to obtain beneficial effects, e.g., a reduction or elimination of the acne, e.g., an eradication or diminishment of the bacteria responsible for acne, e.g., Propionibacterium acnes.

What is claimed is:  
     
       1. A method for treating acne, comprising 
       exposing a region of skin of a subject afflicted with acne to ultraviolet light having wavelengths substantially contained in a spectral band between about 320 to about 360 nm, and a fluence of between about 1 J/cm 2  and about 5 J/cm 2 , so as to produce a biological response in a target within a layer of the region of skin that effectively enhances treatment of the acne without substantially damaging tissue surrounding the target while limiting overall dose of irradiation.  
     
     
       2. The method of  claim 1 , wherein said wavelengths are between about 325 to about 345 nm. 
     
     
       3. The method of  claim 1 , wherein said wavelengths are between about 330 to about 340 nm. 
     
     
       4. The method of  claim 1 , wherein said wavelengths are between 332 and 337 nm. 
     
     
       5. The method of  claim 1 , wherein said wavelengths are about 335 nm. 
     
     
       6. The method of  claim 1 , wherein said ultraviolet light is produced by a nitrogen laser. 
     
     
       7. The method of  claim 1 , wherein said ultraviolet light is produced by a third harmonic of a NdYAG laser. 
     
     
       8. The method of  claim 1 , wherein said treatment is performed at between about 0.1 to about 0.5 minimum erythema dose. 
     
     
       9. The method of  claim 1 , wherein said treatment is conducted over multiple exposure periods. 
     
     
       10. The method of  claim 1 , wherein said treatment comprises prevention of acne. 
     
     
       11. The method of  claim 10 , wherein said wavelength is between about 330 to about 340 nm. 
     
     
       12. The method of  claim 11 , wherein said wavelength is between 332 and 337 nm. 
     
     
       13. The method of  claim 12 , wherein said wavelength is about 335 nm. 
     
     
       14. The method of  claim 1 , wherein said treatment is effected to reduce size or amount of sebaceous glands in exposed skin. 
     
     
       15. The method of  claim 14 , wherein said treatment is performed at between about 0.1 to about 0.5 minimum erythema dose. 
     
     
       16. The method of  claim 14 , wherein said treatment is conducted over multiple exposure periods. 
     
     
       17. A method for treating acne, comprising 
       exposing a region of skin of a subject afflicted with acne to ultraviolet light having wavelengths substantially contained in a spectral band between about 320 to about 360 nm, and a fluence of between about 1 J/cm 2  and about 5 J/cm 2 , so as to produce a biological response in a sebaceous gland within the region of skin that effectively enhances treatment of the acne without substantially damaging tissue surrounding the sebaceous gland while limiting overall dose of irradiation.